Flatten chicken to 1/4-in. thickness. Combine 1/2 teaspoon salt and pepper; sprinkle over both sides of chicken. Set aside.
In a small nonstick skillet, saute onion and garlic in 1 tablespoon butter until tender. Add apple; saute 1 minute longer. Stir in the bread crumbs, basil, rosemary and remaining salt; heat through.
Top each piece of chicken with 3 tablespoons apple mixture. Roll up and secure with toothpicks; coat with flour. In a large nonstick skillet, cook chicken in 1 tablespoon butter until browned on all sides. Remove and keep warm.
Stir apple juice and sherry or additional juice into pan, stirring to loosen any browned bits. Return chicken to pan. Bring to a boil. Reduce heat; cover and simmer for 15-20 minutes or until chicken juices run clear.
Remove chicken to a serving platter; discard toothpicks. Add remaining butter to pan juices; whisk until blended. Serve with chicken.